import math
# math.acos(x) is the arccosine of x.
# math.sqrt(x) is the square root of x.

import string
# string.join(words,sep) takes a given list of words,
#    and returns a single string resulting from concatenating them
#    together, separated by the string sep .
# string.lower(word) converts word to lower-case

import sys

if __name__ == "__main__":
    print "hello world"

